Persona A · 65+
“Mom, I’m in trouble. Send money.”
Phone scams now use cloned voices and AI faces. BVC gives elderly users a single-tap challenge that’s impossible to fake — without explaining what a deepfake is.
BVC · Biometric Verification via Kinematics · iOS
Prove the person
on the call is real.
In fifteen seconds.
A verification channel for the deepfake era. BVC doesn’t analyze video — it asks the other person to physically tilt their phone. Generative models can fake a face. They cannot reach into the physical world.
MOVE YOUR CURSOR · TILT YOUR DEVICE
9:41BVC · LIVE
Verifying counterparty
Tilt to slide the token to the lit zone
REC · 360p
42ms
REMOTE · CALLER
TILT DOWN ↓
TOKENHex · Red
IMU⎡ 0° 0° ⎦
DWELL0.7s
01 The Problem
Video can be synthesized.
Physical motion cannot.
What you see
A face on a video call. Voice that sounds like family. A familiar smile.
Generative models now reproduce faces, micro-expressions, and voices with enough fidelity to deceive — even close relatives. Pixels are no longer evidence.
What you can’t fake
A real human, holding a real phone, tilting it at exactly the right moment.
Generative models cannot reach into physical space. They can render a face, but they cannot lift a phone, tilt it left, then right, on demand, in front of you.
02 How it works
A 15-second proof of presence.
Step 01 · Share
Send a one-tap link from inside any call.
You’re on WhatsApp, FaceTime, WeChat — anything. Suspicious? Open BVC, tap once, drop the verification link into the chat.
hbcp.io/v/A3K-7BXJOIN
Step 02 · Tilt
The other person tilts their phone to a hidden target.
The server picks a secret kinematic mapping (g’). The token only reaches the lit zone if a real human is physically tilting a real device.
Step 03 · Verified
You see the result, side-by-side.
Cryptographically signed by the device’s Secure Enclave. No video stored. No identity data exchanged. Just one binary truth: present, or not.
✓
03 Time on task
Pop-in. Verify. Pop-out.
BVC isn’t a video-call replacement. It’s a verification channel that sits beside whatever you already use. The whole thing — open, verify, close — happens in the time it takes to refill your tea.
Tap [Verify]
0s
Share link
2s
They join
5s
Confirm identity
7s
Tilt → Lock
14s
Verified ✓
15s
Designed to finish in well under 20 seconds. Built for users 60+, tuned to run smoothly on hardware as modest as an iPhone SE.
BVC v1.0
04 Privacy
The most private way to prove someone is real.
BVC never records, processes, analyzes or transmits a single video frame. Verification is a kinematic signature — accelerometer and gyroscope data — signed by the device’s Secure Enclave. Video flows peer-to-peer for fifteen seconds, then disappears.
- NOVideo recording. Not on device. Not on server. Anywhere.
- NOFacial recognition or biometric template extraction.
- NOAccount, name, phone number, or email required.
- NOTracking, advertising IDs, or third-party SDKs.
- YESAn encrypted local audit log of timestamps and hashes — yours alone.
EPHEMERAL P2P · 360p · 15s
05 The protocol
BVC. Biometric Verification via Kinematics. Patent Pending
A challenge that lives in physical space.
The server generates three things: a target zone τ, a secret kinematic mapping g′, and a session nonce N. The challenged device receives them, samples its IMU at 50 Hz, and streams the resulting trajectory back, signed by Secure Enclave.
The server reapplies g′ to the raw IMU data and confirms — by normalized cross-correlation ≥ 0.85 — that the trajectory is consistent with a real person, holding a real device, in real time.
τtarget zone (1 of 6)
g′kinematic map (K = 4)
Nsession nonce, single-use
IMU50 Hz · attitude + accel
NCC≥ 0.85 required
σSecure Enclave signature
Tdwell0.5 s
Tinteract≤ 10 s
videonever inspected
06 Use cases
Designed for the moment something feels off.
Persona B · Family
Routine safety check-ins.
Verify a parent abroad, a child away at school, a partner in transit. A weekly cadence of presence-proofs becomes part of how a family stays safe.
Persona C · General
High-stakes calls and unfamiliar faces.
Wire transfers. Job offers. New clients. Anywhere a face on a screen is being trusted with consequence — drop a BVC link, get a binary truth in fifteen seconds.
PRESENCE · VERIFIED
07 FAQ
Questions, quietly answered.
01Is this a replacement for FaceTime, WhatsApp, or WeChat?+
No. BVC is a verification channel — a tool you open for fifteen seconds when something feels off, then close. It works alongside whatever video app you already use. The whole interaction is designed to feel like a one-tap signature, not a phone call.
02Why tilting? Why not blink-detection or face-movement?+
Pixel-based liveness checks fail against modern generative models. Tilting requires the challenged party to physically move a real device through real space. A deepfake on a remote screen cannot do that. The motion is also visible to you — you can watch the phone tilt while the token moves on your screen, and notice immediately if they don't match.
03Does BVC record video or use facial recognition?+
Never. Video flows peer-to-peer at 360p for ~15 seconds, then disappears. The server only ever sees signed motion data — no pixels, no facial templates, no biometric extraction. The audit log on your device contains only timestamps, result codes, and cryptographic hashes.
04What stops someone from forwarding the link to a coconspirator?+
Two layers. First, the link is single-use and expires in 2 minutes. Second, before verification begins, you visually confirm the person on the BVC video is the same person you were already speaking to. The kinematic challenge then proves the device is being physically operated. Together, this defeats relay attacks.
05Will my elderly parent be able to use this?+
BVC is built for them. No account, no login, no typing. One large button to start. One large button to verify. Tap-targets exceed Apple's minimum by 35%. Audio cues at every step. Designed for first-time and older users, and tuned to run smoothly on hardware as modest as an iPhone SE.
06Is this legal evidence?+
No, and we are explicit about it. A BVC record proves the device was physically operated by a human at a stated time. It does not prove the operator's legal identity, and it is not court-admissible without further authentication. Treat it as a high-confidence safety signal, not a signed deposition.
07Why iOS only, for now?+
App Attest and Secure Enclave give us a stable hardware-rooted identity without OEM fragmentation. Android arrives in Phase 2 once protocol behavior is fully validated.
08 Manifesto
For most of human history, seeing was believing.
That arrangement just ended.
BVC is a small instrument for a quieter kind of trust — one that does not ask the camera what is real, but reaches past it, into the physical world, and finds something there.
A real hand. A real phone. A real human, present.
— BVC · Copenhagen · 2026
09 Get in touch
Trust, in fifteen seconds.
BVC is live today on iOS via private TestFlight. We’re opening conversations with investors and design partners as we move from demo to production — particularly teams working on fraud prevention, elder care, or remote-identity verification. Leave a few details below and we’ll follow up.